par JUSTIN ANDREI*, CONSTANTIN CALOTA**
* Institut de Géologie et Géophysique, Bucarest
* Université de Bucarest, Faculté de Géologie et Géographie,
Bucarest
Porphyry type mineralization in Metaliferi Mountains are developed into subvolcanic
bodies occupying the most part of its volume, the copper minerals being very
tightly associated in space with the magnetite.
The magnetic anomalies generated by these bodies reflect both the space disposition
of the mineralization and the host structure. These very favourable physico-geological
conditions made possible a structural study by means of modeling of magnetic
anomaly sources.
The paper deals with the magnetic modeling process, using the Talwani method
in the case of subvolcanic structures from Rosia-Poieni and Bucium-Tarnita,
both having a porphyry-copper mineralization with magnetite.
The magnetic modeling of the Rosia-Poieni structure was realized knowing very
well the geometric parameters of the subvolcanic body and also the distribution
of the magnetic susceptibility values down to 1200 m. The comparison between
the actually mapped magnetic anomaly and the calculated, by modeling, anomaly,
give the possibility to establish the conditions in which the interpretation
procedure can be used in a case for which the geology is well known.
The magnetic modeling of the Bucium-Tarnita structure was done having incomplete
information concerning the geometry of the subvolcanic body and the distribution
of the magnetic susceptibility values. The model built up in this case by a
trial and error process using all available geological and geophysical data
can be useful to guide the future geological investigations.